On this typical, suburban street there's a space directly contiguous to the curb that creates distance between the whizzing cars and the relative safety of the sidewalk. It's a strip of grass seven feet wide.
It is maintained by a homeowner who uses gasoline made from petroleum to mow it short, and nitrogen fertilizer made using natural gas to keep it growing tall. Weeds are kept under control by using pesticides that wash into the gutters and down the storm water system into creeks where they pollute the water supply of both humans and all other creatures down stream. The lots on this street are 100 feet wide creating 700 square foot green strips in front of each home. John Jevons, states that it's possible for even a modest farmer to raise 200 pounds of potatoes per year in a 100 square foot area. That's a possible 1400 pounds of potatoes per house. At 330 calories per pound that's a total of 462,000 calories or 45% of the calories necessary to sustain the average teenage male for entire year. If he really likes potatoes.
It appears possible if you live on this street to reduce the amount of gasoline you use, reduce the amount of air pollution your dirty lawnmower belches out, reduce the about of natural gas used to make commercial fertilizers and reduce the amount of chemical pollutants in our water system all while growing almost half the calories your son will need for a year in an area that is not consider arable. I'm not really suggesting that this specific part of your plot is the best place to start actively cultivating land currently considered unfit for raising food. Or that man can live on potatoes alone. Maybe just the idea of starting to grow food in your front yard flower bed is enough (and you're going to want to add in some beans and tomatoes) but it does begin to suggest that our current definition of where we can grow food is in need of an update.
Typically we describe land capable of supporting food production as arable. But what is arable land? Of the 57 million square miles of dry land on Earth, approximately 12 million square miles, or 21%, are considered arable by traditional standards. The inverse term, Unarable, applies to the rest of the surface of the planet; hose areas that aren’t typically thought of as able to support food production. Typically these areas are too cold or too hot; too wet or too dry; too shady or too rocky or too steep for traditional agriculture. There it is again, “traditional agriculture.” What does that mean? Typically agriculture is defined as the systematic production of “food, feed and fiber” using domesticated plants and animals. Humans have been doing it for 10,000 years with varying degrees of success. Recently though the cyclic processes that governed this way of harvesting from nature have been replaced by a linear processes that substitute hydrocarbons for human & animal labor as well as nutrient recycling. We human beings have been experiencing a temporary vacation from the cycles that sustained us for thousands of years. And as a result we’ve paid little or no attention to the knowledge base necessary to do so. We’ve become complacent because of our cheap, abundant energy; paying no real attention to the idea that careful stewardship of the land is the only real way to ensure long term thrival of our species.
But now I’ve gone off on a tangent. I was talking about arable land and “traditional agriculture.” Far from being a non-traditionalist, I think the best place to start when considering our food future is to look back at history and learn the lessons it has to teach us. After all, the use of hydrocarbons to replace cycles with linear processes is a rather recent development. So how did humans get by before the age of cheap oil and natural gas in terms of raising plants and animals to eat? They grew food where they lived.
But how can an updated version of our attempts to farm change the way we think about where farming is possible, probable or even a good idea? The truth is farming is possible in many places not typically considered arable. The above example of an underutilized strip of grass next to a road way is but one example of space that can provide calories. Rooftops, patios, porches and even in our cars, people can used any and all available space to farm. It seems to me that any attempt to promote farming or the growing of one’s own food must examine an attempt to use existing resources for doing so. An old tire and some fallen leaves is enough to start growing potatoes on your patio. Ingenious ideas about using the trappings of modern life to contain soil and water in a sunny spot can yield food for you and your family. Arable land need not be only flat, rich soil in sunny spots located in temperate climates. Human ingenuity should be mined in an effort to expand where and how we grow our food.
Truck Farming - think it isn’t possible to grow food in your truck bed? ;-)